title: Orthodontic bonding to acid- or laser-etched prebleached enamel.
abstract: OBJECTIVE
  Bonding forces of brackets to enamel surfaces may be affected by the procedures used for bleaching and enamel etching. The aim of this study was to investigate the bonding strength of orthodontic brackets to laser-etched surfaces of bleached teeth.
  
  
  METHODS
  In a nonbleached control group, acid etching (group A) or Er:YAG laser application (group B) was performed prior to bracket bonding (n = 13 in each group). Similar surface treatments were performed at 1 day (groups C and D; n = 13 in each subgroup) or at 3 weeks (groups E and F; n = 13 in each subgroup) after 38% hydrogen peroxide bleaching in another set of teeth. The specimens were debonded after thermocycling.
  
  
  RESULTS
  Laser etching of bleached teeth resulted in clinically unacceptable low bonding strength. In the case of acid-etched teeth, waiting for 3 weeks before attachment of brackets to the bleached surfaces resulted in similar, but not identical, bond strength values as those obtained with nonbleached surfaces. However, in the laser-etched groups, the bonding strength after 3 weeks was the same as that for the nonbleached group.
  
  
  CONCLUSIONS
  When teeth bleached with 38% hydrogen peroxide are meant to be bonded immediately, acid etching is preferable.
authors.affiliation: Department of Orthodontics, Faculty of Dentistry, Yeditepe University, Istanbul, Turkey.
authors.forename: Fulya
authors.initials: F
authors.lastname: Ozdemir
authors.forename: Umut
authors.initials: U
authors.lastname: Cakan
authors.forename: Nese
authors.initials: N
authors.lastname: Gonul
authors.forename: Derya
authors.initials: D
authors.lastname: Germec Cakan
keywords: Bonding; Decalcification; Laser